This invention relates to improved apparatus for connecting and disconnecting threaded joints in a string of well pipe.
In order to facilitate the making and breaking of threaded connections in a well drilling pipe string, a power operated tool is sometimes employed, being mounted to a support structure at a side of the drill pipe and having means adapted to project into engagement with the pipe to relatively rotate two sections thereof in order to screw them together or apart. Tools of this type may include a spinner device for rotating an upper section relatively rapidly into or out of connection with a lower pipe section, and may also include a torque wrench assembly operable to exert a greater torque on the pipe sections to either complete the final connecting action or initiate unscrewing rotation of the sections.
One disadvantage of previously devised tools of this type has been that in some installations the presence of the tool on the rig at a side of the drill pipe has tended to interfere with performance of other operations on the rig, and thus introduce inefficiency into the overall drilling process.